Method and means for ultrasonic activating of solvent and sand solution



J. R. LOGAN S FOR Feb. 28, 1961 METHOD AND ME ULTRASONIC ACTIVATING OFSOLVENT AND SAND SOLUTION Filed Feb 4, 1958 uomsom mm Om INVENTOR.

JAMES R. LOGAN ATTORNEY were! raised 1 METHOD AND MEANS FOR ULTRASONICACTI- VATING F SOLVENT AND SAND SOLUTION Filed Feb. 4, 1958, Ser. No.713,251

4 Claims. (Cl. 208-11) This invention relates to ultrasonic cleaningmethods and means. While not limited thereto it is especiallyadvantageously used in oil removal both in degreasing small machineparts and the like and in recovering oil by extraction from oil bearingaggregate materials such as sand, clay, silt and similar materials.

An object of the invention is to provide improved methods and means foraccomplishing ultrasonic cleaning.

Another object is to provide a novel method and means for removing oilfrom such elements as those hereinbefore described.

Another object is to provide a cleaning method in which the ultrasonicwave energy is more efiiciently utilized. In the past when an article orelement was to be cleaned ultrasonically, it was simply immersed in aliquid which was ultrasonically activated to produce cavitation. Theelements were permitted to rest on the container bottom and on top ofone another; but doing this has several undesirable eifects. Thearticles to be cleaned almost always have a different acoustic impedancethan the cleaning liquid resulting in reflections of the wave so thatlittle or no wave energy reaches certain areas of the elements to becleaned. Moreover, the reflections often create standing waves in thefluid which prevent cleaning even in some areas which are reached by theultrasonic waves. Different loading of the cleaner and differentplacement of the load with each use make it virtually impossible toovercome the problem by design change in the cleaning apparatus.

However, in the invention the problem is substantially solved, andcertain of these objects are realized, by dropping the soiled elementsdown through a column of cleaning liquid which is ultrasonicallycavitated and letting those elements tumble and turn whereby allsurfaces will be contacted by the cavitating liquid. Advantageously theliquid is circulated past the elements in the direction counter toelement movement so that the liquid is always fresh and so that thecleanest elements are immersed in the cleanest liquid. The liquid shouldbe a solvent for the soil.

The time required for ultrasonic cleaning is very short but in previousmethods much of this advantage is lost because of the necessity forrepositioning the elements being cleaned or for extending the cleaningperiod in the hope that areas in which cleaning is less eifective willeventually become clean. Another object of the invention is to utilizethe rapid cleaning action of ultrasound and to accomplish more uniformcleaning.

Other objects and advantages of the invention will hereinafter appear.

The following is one specific example of the process:

lulped oil sand is continuously dropping into a column of kerosene whichis subjected for a vertical distance of approximately ten feet tocavitation by ultrasonic action. The cleaned sand is continuouslycollected at the bottom of the column and is lifted upwardly to a heightabove the liquid column. The kerosene column is continuously changed byflowing kerosene down through the rising sand and thence up in thecolumn to its upper level where the kerosene and oil are removed.

The accompanying drawing is a schematic showing of a system of apparatusfor practicing the invention which embodies the invention and which isadvantageously used in practicing the method described in the example,it being understood that various modifications may be made in theprocess described and that other process, systems, and apparatusembodying the invention may be practiced and made without departing fromthe spirit of the invention or the scope of the appended claims.

Referring to the drawing, the system there shown comprises means forcontaining a vertical column of liquid solvent, means for ultrasonicallyactivating the solvent to produce cavitation, means for droppingelements to be cleaned into the solvent, means for collecting thecleaned elements and transporting them above the liquid level, and meansfor flowing the solvent in a direction counter to element movement.

Advantageously the system comprises an elongated container verticallydisposed, such, for example, as the cylindrical tank It? having asolvent outlet 12 near its upper end, a solvent inlet 14 near its lowerend, and a solvent inlet and element collecting point 16 at its bottomend. Conveyor means in convenient form, and here shown as an enclosedauger 18 beginning at the collection point 16, extends upwardly at anangle to a level above the solvent outlet 12. where cleaned elements,such as the sand illustrated, are discharged at an opening 20 into acollection hopper 22.

Clean solvent, such as the kerosene shown, is intro duced at fill pipe24 to a storage tank 26 having two outlets 28 and 39, including controlvalves 32 and 34 which are connected to inlet 14 and inlet 36respectively. Inlet 36 is in the conveyor housing 38. The solvent flowsdown past the conveyor auger, and through inlet 114,- into the lower endof container 10 and thence up in the container to outlet 12 where it ispumped away by a suitable pump at The pump and valves 32 and 34 areadjusted to maintain the liquid level in the container 10 near its topas shown.

A plurality of transducers, such as the magnetostrictive transducers 42illustrated, are attached in wave transmitting relation, as for exampleby welding, at vertically spaced points along one side of container 10.The transducers are connected as shown to an electrical ultrasonic wavegenerator 44 which, in turn is energized by a source of electrical power46.

In operation of the system, oil sand contained in hopper 48 is passed toa conveyor 50 driven by prime mover 52 from whence it is dropped intocontainer lit whose solvent is subjected to cavitation by the action oftransducers 42. The sand falls freely down through container 10 and itssolvent, tumbling and turning. The oil is extracted and removed from thesand by the cavitation action and is thereupon dissolved by the solvent.Collecting at the bottom of tank 10, the sand is picked up by auger 18,which is turned by its prime mover 54, and is elevated out of thesolvent and then falls out of opening Zti into hopper 22..

During this action solvent flows counter to the sand movement aspreviously described.

As it is used herein, the word ultrasonic refers to mechanical waveaction and does not refer to a wave action limited to any frequency orfrequency range within or without the range of audible frequencies.

I claim:

1. The method of removing oil from oil bearing elements which comprisesdropping said elements into a solvent for oil, permitting said elementsto fall free Fatented Feb. as, 19st through said solvent, andultrasonically activating said solvent to the degree necessary to causecavitation in the solvent as the elements so fall through it.

2. -Themethocl defined in claim 1 in which the solvent is made to flowupward as the elements fall through said solvent. 7

3. The continuous process for removing oil from oil bearing elementswhich comprises dropping a continuing supply of said oil bearingelements into a solvent for the oil, permitting said elements to fallfree through said solvent, ultrasonically activating said solvent to thedegree necessary to produce cavitation in the solvent as the elements sofall through said solvent, collecting the fallen elements andcontinuously elevating said elements to a level above the level of thesolvent.

4. The process defined in claim 3 in which the solvent is caused to flowcontinuously downwardly around the elements being elevated and thenceupwardly through the falling elements.

References Cited in the file of this patent UNITED STATES PATENTS1,791,797 Clark Feb. 10, 1931 2,545,938 Bilbe Mar. 20, 1951 2,559,257Obey July 3, 1951 2,722,498 Morrell et a1. Nov. 1, 1955 2,742,408 LaPorte Apr. 17, 1956 2,825,677 Coulson Mar. 4, 1958 2,871,180 Lowman eta1. Jan. 27, 1959 Notice of Adverse Decision in Interference InInterference No. 93,484 involving Patent No. 2,973,312, J. R. Logan,Method and. means for ultrasonic activating of solvent and sandsolution, final finclgment adverse to the patentee was rendered. Oct.15, 1964, as to claim 1.

[Ofioial Gazette Decembea" 22, 1964.]

1. THE METHOD OF REMOVING OIL FROM BEARING ELEMENTS WHITH COMPRISESDROPPING SAID ELEMENTS INTO A SOLVENT FOR OIL, PERMITTING SAID ELEMENTSTO FALL FREE THROUGH SAID SOLVENT, AND ULTRASONICALLY ACTIVATING SAID